Apparatus for passing flowing air about a bed occupant at selective temperatures



May 20, 1959 E. H. DINGMAN 3,444,922

' APPARATUS FOR PASSING FLOWING AIR ABOUT A BED OCCUPANT AT SELECTIVE TEMPERATURES Filed Dec. 6, 1966 Sheet EDWARD H.DINGMAN BY ATTORNEYS May 20, 1969 E. H DINGMAN 3,444,922

APPARATUS FOR PASSING FLOWING AIR ABOUT A BED OCCUPANT AT SELECTIVE TEMPERATURES Sheet Filed Dec. 6, 1966 INVENTCR EDWARD H. DINGMAN AT TORNEYS United States Patent 3,444,922 APPARATUS FOR PASSING FLOWING AIR ABOUT A BED OCCUPANT AT SELECTIVE TEMPERATURES Edward H. Dingman, 8290 Chatfield Ave., Littleton, Colo. 80120 Filed Dec. 6, 1966, Ser. No. 599,429 Int. Cl. F2511 29/00 US. Cl. 165-26 4 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for regulating the conditions of the air surrounding a bed occupant where there is pro duced a low volume of air flow which is selectively heated or cooled and then directed at a controlled rate in a diffused pattern under a covering and about the body of a bed occupant in a progressive flow to provide a continuous air exchange at a selected temperature about the bed occupants body.

This invention relates to a method and apparatus for regulating the temperature and humidity of the air about the body of a bed occupant. The body of the average person releases a substantial amount of heat through skin loss and moisture due to perspiration to the surrounding air. The usual practice of covering the body during sleeping has the effect of insulating the body from the surrounding room air and thereby holds such released heat and moisture in the air about the body.

In cold weather when the room temperature may be below 70 F. heavy covering is frequently employed so as to minimize the exchange of air about the body with the surrounding room air and thus has the effect of increasing the air temperature and humidity about the body. In such instances a person will often throw off the covering while asleep, which will then result in chilling. In

warm weather when the room temperature is above 70 F., a lighter covering is usually employed but the moisture which results from perspiration is still retained about the body by the insulating covering, causing personal discomfort and results in poor rest.

The obese and the bedridden are particularly troubled by these conditions of the air environment about the body. Many home and hospital patients have body temperature conditions which ideally require controlled surrounding air and humidity conditions within the bed environment.

Room air conditioners which have heretofore been provided for regulating the room air temperature and humidity conditions have the disadvantages of handling large volumes of air, requiring special electrical power, and are relatively expensive for installation, operation and maintenance costs. Even with room air conditioners, the person usually employs some form of covering which insulates the body from the surrounding air so there remains no suitable means of exchanging the air between the body and the covering of the occupants bed.

Accordingly, it is an object of this invention to provide a novel method and apparatus for regulating the temperature and humidity of the air about the body of a bed occupant.

Another object of this invention is to provide a small volume low pressure apparatus which is small and compact in size and economical to use for regulating the conditions of air about the body of a bed occupant.

It is still another object of this invention to provide a method and apparatus for regulating the temperature and humidity of the air about a bed occupants body independently of the room air conditions which will remove body generated heat and moisture during warm weather conditions and add the required heat to the air surrounding a bed occupant during cold weather conditions.

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Another object of this invention is to provide a novel apparatus for regulating the air conditions about the body of a bed occupant which is suitable for both home and hospital therapy applications for one or more bed occupants.

Other objects, advantages and capabilities of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings in which like parts bear similar reference numerals.

Briefly stated, in carrying out the objects of this invention there is provided a novel method and apparatus in which there is supplied a low volume, low pressure positive air flow at selected temperatures in a dilfused pattern under the covering of an occupied bed which controls the humidity and the temperature of the air surrounding an occupant of the bed. In apparatus embodying the present invention one or two similar arrangements may be conveniently provided for a double bed to independently accommodate two persons in that bed.

In the drawings:

FIG. 1 is a perspective view of an arrangement embodying my invention inclusive of a cabinet and associated hand control box and air distributor head in combination with a bed and bed occupant drawn to a reduced scale as compared to the box and distributor head illustrating the movement of the air about the body of the bed occupant; and

FIG. 2 is a schematic diagram of apparatus embodying my invention utilized in the arrangement shown in FIG. 1.

Referring now to the drawings, in FIG. 1 there is shown a bed 2 having the body 3 of a bed occupant illustrated in a prone resting or sleeping position and covered by an upper layer 4 of bed covering. Adjoining the bed 2 there is shown a typical cabinet 6 for enclosing and supporting air control apparatus hereinafter described more fully.

The cabinet 6 as illustrated is arranged for dual service for independently regulating the air about the bodies of two persons disposed on each side of a double bed. Similar structure is shown on one end wall 7 of cabinet 6 for such dual service for the purposes of illustration, but for the sake of simplicity the apparatus required for the single body 3 will be specifically described hereinafter with the understanding that similar structure incorporated into cabinet 6 will be suitable for dual service. As shown in FIG. 1 the end wall 7 supports an air outlet 8, an electric power switch 9, a remote control box inlet plug 11, and an electric power inlet plug 12.

A remote hand control box 13 having a scale 14 and dial 15 is positioned at one side of the bed 2 for setting the apparatus for a desired body requirement by the bed occupant. An electric cord 16 is connected between box 13 and the inlet plug 11 to connect the control box 13 into the apparatus contained in cabinet 6. For some uses the control box 13 may be positioned remote from the bed occupant when desired as for example in hospitals when a nurse and not the patient should make the control box setting. It is also understood that other forms of selectors may be used in place of the control box 13 such as sensors placed in such a position as to monitor bed temperature and humidity conditions. These sensors may be utilized to render the apparatus fully automatic in adjusting the temperature and humidity about the body of a bed occupant.

A distributor head 5 is positioned at the foot of the bed 2 and has a hollow and necessarily a flexible hose or conduit 17 connecting it to the air outlet 8 to pass air under pressure from the cabinet 6 through the distributor head 5 in a diffused pattern and under covering 4 and to circulate in a progressive flow about the body 3 of the bed occupant. Distributor head 5 may be of various structural forms which in general include spaced upper and lower surfaces forming an elongated narrow passage in communication with conduit 17. For best results the bed will be provided with an upper and lower or divided layers of bed convering with the upper and lower surfaces of the head 5 sealed thereto to provide air channels.

The cabinet 6 includes an air filter 18 forming a portion of each side thereof to purify the air taken into the apparatus in the cabinet and a handle 19 on its top to facilitate its carriage to desired locations making the apparatus essentially portable. This cabinet may be of various shapes and sizes, but a unit on the order of six inches wide, eight inches high and then inches deep which may be suitable for placement under the bed has been found capable of housing apparatus of the type hereafter de scribed and capable of dual service for persons in a double bed. For dual service a second distributor head member should be positioned preferably at the foot of the bed on the other side of that shown in FIG. 1. It has been found that the bed covering for two persons in a double bed normally lays in such a pattern that the air flowing around one person is separated from the other and the air flow for two persons in a double bed would be essentially the same in volume for both persons but independent in temperature and humidity levels. These are set independently by each bed occupant.

The apparatus contained in cabinet 6 is illustrated in a schematic manner in FIG. 2 and in general includes an air pump 22 driven by a mechanical drive assembly 23, a temperature exchange chamber or plenum 24, a valve drive and clutch assembly 25, and electric circuitry 26 coupled in a functional interrelationship with the apparatus located exteriorly of the cabinet 6 as previously described including the flexible conduit 17 and associated distributor head 5, control box 13, and electric power inlet plug 12 through which a source of electric power (not shown) is connected. Electric lines designated 27 and 28 are connected to the plug 12 and will hereafter be referred to as the electric power lines which provide standard AC. power to the apparatus. Switch 9 is connected in line 28 to disconnect the electric power and turn off the apparatus.

Air pump 22 is preferably of the double chambered bellows type and is provided for supplying a substantially continuous low pressure, low volume stream of air. This pump has an output capacity of about 3-5 c.f.m. and will force from one to two c.f.m. of air in a progressive flow over the body of the person in bed. The bellows in cludes an intermediate support 30 having elongated hollow fiexure members 31 and 32 supported on each side. These fiexure members are preferably of a plastic material. The outer ends of the fiexure members are closed with head portions 33 and 34, respectively, in which are formed air intake passages 35 and 36, respectively. Air filter 18 is disposed adjoining the inlet of each intake passage for purifying the air entering the fiexure members. Intake valves 37 and 38 preferably of the flap type of a plastic material are pivotally secured on an inner surface of the associated head members at the intake passages 35 and 36, respectively, to normally close these passages and then open the passage in response to air being drawn into the fiexure members 31 and 32.

Air discharge passages 41 and 42 are formed in coaxial and opposing relation in the support 30 which are in communication with a common discharge passage 43 extending transversely thereof through one end of the support 30. Passage 43 forms the air discharge outlet of the air pump 22 and is of a selected sectional dimension. Discharge valves 44 and 45 of the flap type are pivotally secured on the support 30 in the common discharge passage 43 and alternately open and close passages 41 and 42, respectively.

A shaft or connecting rod 46 extends through the center of the air pump 22 along its lengthwise extent and is fixedly connected at one end to head portion 33 and intermediate its end to head portion 34 so that when reciprocated back and forth alternately expands and contracts the fiexure members 31 and 32. This reciproeating action compresses the air in one of the fiexure members forcing air under pressure through its associated discharge passage while at the same time expanding the other fiexure member with the intake and discharge valves functioning so air is continuously being pumped through the common discharge passage 43 during reciprocation of the shaft 46.

The mechanical drive assembly 23 for the bellows comprises a drive motor 44 of the electric type electricalconnected to the electric power lines 27 and 28. A gear box 47 for speed reduction is coupled to the output shaft of motor 44 to reduce the speed of the motor to a required slow speed. The preferred rating of the motor 44 is 4 hp. at 1800 r.p.m. with a to 1 speed reduction ratio of the gear box 47. The output of the gear box 47 is coupled to a crankshaft 48 having an intermediate throw portion 49 coupled to the end of the connecting rod or shaft 46 so as to reciprocate shaft 46 as indicated by arrows at a slow speed. The rotation of the crankshaft is also used to drive the valve drive and clutch assembly 25 as hereafter described.

The temperature exchange chamber or plenum 24 comprises a hollow sealed housing 51 having a central hollow partition member 52 dividing it into separate elongated heating and cooling passages 53 and 54. The heating and cooling passages have a common air intake passage 55 joined to the common discharge passage 43 of the air pump by a hollow conduit 56 of a selected sectional dimension. A valve 57 is disposed at the discharge end of the heating and cooling passages of the housing in air receiving relation thereto to regulate the temperature and discharge flow of the air passing from the chamber 24 through the air outlet 8 and flexible conduit 17 to the distributor head 5. Valve 57 may be of various types and in one form may be a plate valve pivoted about a central discharge end point of the inner partition member 52 so that each angular setting would control the air flow from either the cooling or the heating passages as required to obtain a selected output air temperature.

For supplying heat to the heat passage 53 there is provided an electric heating element 58 disposed in an intermediate portion of the heat passage 53 having a larger sectional dimension than either its intake or discharge ends. The heating element 58 is electrically connected to the power supply lines 27 and 2 8 through a temperature sensitive switch or thermostat 62 disposed in passage 53 and a manual switch 63 exteriorly of the chamber. Thermostat 62 has contacts which open at a desired temperature of the chamber 24 to control its upper temperature limit. A possible alternative to thermostat 62 would be a phase control SCR which for some applications would eliminate arcing.

For supplying cooling to air flowing in the cooling passage 54 there is provided a cooling coil 64 disposed intermediate of its intake and discharge ends which forms a part of a refrigeration assembly including an expander 65, a head radiator coil 66 and a sealed compressor 67 coupled in fluid flow relation and disposed exteriorly of the chamber 24. The cooling coil 64 is mechanically isolated from the air flow as a safety precaution. The refrigerant used is non-toxic so that a leak will not pose a hazard to the sleeper. Adequate heat may be obtained by providing aluminum or other high thermal conductive heat paths (not shown). The compressor 67 includes an electric motor (not shown) having two terminals 68 and 69 connected to power lines 27 and 2-8. A thermostat 70 is disposed in the cooling passage 54 and with a manual switch 71 is electrically connected between terminal 68 and line 28 to shut off the compressor motor when either is opened. The thermostat 70 has contacts which open at a desired temperature to control the lower temperature limit of the chamber or plenum 24. A second thermostat 72 is electrically connected across terminals 68 and 69 and to a third terminal 73 of the compressor motor. Thermostat 73 is disposed exteriorly of the refrigerator assembly and has contacts which open when the air surrounding the refrigerator is below a desired level.

While a conventional refrigerator assembly as described is suitable, an alter-native form would be the use of a thermoelectric cooling unit.

The valve drive and clutch assembly 25 for selectively moving valve 57 to a desired setting includes an input shaft 74 preferably disposed in an upright position and inclusive of opposing upper and lower oppositely inclined bevel gear portions 75 and 76, respectively, at one end. An output shaft 77 extends transversely of input shaft 74 and has one end operatively connected to valve 57 and the other end supports a bevel gear 78 adjoining gear portions 75 and 76. A lever am 79 is pivotally secured at its upper end to a point on shaft 74 intermediate gear portions 75 and 76 and is supported in an upright position by left and right side balance springs 80 and 81. Pivotal movement of the lever arm 79 to the right or left as indicated by arrows moves either the upper or lower gear portions 75 and 76 into engagement with gear 7 8 so as to transmit the rotary motion of input shaft 74 to the output shaft 77 either in a clockwise or counterclockwise direction depending on whether the lever arm is moved to the right or to the left.

Slow speed rotary motion is imparted to the input shaft 74 by means of a suitable drive which is preferably the rotary motion of crankshaft 48 hereinabove described. A suitable coupling such as a pulley or a gear 82 on the end of crank 48 is shown in meshing relation with a larger gear 83 on input shaft 74. This drive arrangement for shaft 74 will reduce its rotation to a preferred speed of approximately 5 rpm. The same crankshaft 48 and gear 82 may be used to drive a similar larger gear 83a of a similar drive shaft and clutch assembly in the dual service apparatus for the other side of a double bed.

Electric control circuitry 26 is provided between the control box 13 and lever arm 79 to move the lever arm by means of the actuation of a balanced solenoid having a core portion 84 connected at one end to the depending end of the lever arm 79 and a coil portion 85 surrounding the core portion 84. This electric circuitry as illustrated is essentially a servo-type control and includes an electric power conversion stage for providing filtered DC. power to a bridge circuit and two transistors hereafter described. This power conversion stage includes a stepdown transformer having a primary winding 86 conneetedto power lines 27 and 28 and two secondary windings '87 and 88. The AC. power at the secondary winding 87 is converted to DC. by means of a diode and filtering series resistor and parallel capacitors generally designated 89. The AC. power at the secondary winding 88 is converted to DC by means of a diode and filtering series resistor and parallel capacitors generally designated 89. The AC. power at the secondary winding 88 is converted to DC. by means of a diode and filtering series resistor and parallel capacitors generally designated 90.

The bridge circuit generally designated 93 comprises four branches. The first branch includes a variable resistor or null pot 94 having its tap mechanically coupled to shaft 77 as indicated by broken lines which changes its electric resistance in accordance with a position of rotation of shaft 77. This arrangement provides a feedback or servomechanism arrangement for changing the bridge in accordance with a selected setting of valve 57. A thermal sensitive resistor or thermistor 95 is connected in series with pot 94 in the first branch. The second branch comprises a fixed resistor 96. The third branch of the bridge oppositely of the first branch has a fixed resistor 97. The fourth branch oppositely of the second branch comprises a variable resistor 98 forming the circuitry contained in control box 13 and has an adjustable tap connected to dial 15. Resistor 99 is connected across the output of the bridge circuit 93 and has a ground connection at its midpoint. The output of the bridge circuit 93 is connected to the ends of the solenoid coil 83 through the base and emitter elements of amplifying transistors 101 and 102 which have their emitter elements connected to ground.

The converter arrangement 89 is connected to the input of the bridge circuit to provide bias power therefor and the converter arrangement is connected to a point on the solenoid coil portion to provide power to the collectors of transistors 101 and 102. In this manner the output of the bridge circuit 93 is amplified through transistors 101 and 102 to excite the solenoid coil portion "85 and move the solenoid core portion 84 left or right in accordance with a setting of the resistor 98 through dial 15.

A shift of the core 84 to one side or the other produces a slight rotation of shaft 77 through clutch 25 which changes the setting of resistor 94 until the bridge again reaches a null point commonly called a balanced condition and the core and the lever arm returns to a central null position as shown under the influence of springs 80 and 81.

The thermal element or thermistor is positioned at the air intake of the flexure members of the air pump 22 as shown in broken lines so that changes in air temperature unbalances the bridge circuit by changing the resistance in the first branch and the valve setting is adjusted accordingly so that a temperature rise of the air drawn into the bellows proporionally reduces the air temperature directed through head 5 and a lower temperature of air drawn into the bellows changes the setting of the valve so that the temperature of the air directed through head 5 is proportionally increased. For best results the room ambient value of resistance of thermistor 95 must be ap proximately V of the resistor 94.

It is understood that various forms of control systems may be provided for changing the setting of valve 57. An alternative control system of the pneumatic type is to provide a small air bellows coupled by suitable linkage to the dial of the operator control box adjoining the bed and a similar small air bellows coupled by suitable linkage to the valve 57 in the cabinet. These bellows will be joined in a closed air system relationship by an elongated tubular member or air line extending from the control box to the cabinet as does electric line 16 of FIG. 1. In this manner any change in the dial setting of the control box moves to expand or contract its associated bellows to expand or contract the remote bellows through the line and thus change the setting of the valve 57. In this system a room temperature responsive sensing element may be provided by using a bimetallic thermostat coupled directly to the valve 57 and specifically it is disposed at the pivot of a valve of the plate type and secured to the plate with its metallic element exposed to the room air so that a change in room temperature will alter the angular seting of the plate-type valve.

In general operation purified air entering the air pump 22 is passed through restricted passage of conduit 56 in a continuous flow by reciprocating the bellow flexure elements 31 and 32. The temperature of the air is altered in the plenum or temperature exchange chamber 24 by passing through either the heating passage 53 or cooling passage 54 in accordance with the setting of valve 57. This setting is regulated by the setting of control box 13 which in turn actuates the valve drive shaft 77 through circuitry generally designated 26.- In the event of a substantial change of room temperature, the temperature element 45 located adjoining the air intake of the bellows alters the electric circuitry 26 to adjust the setting of valve 57 to increase or decrease the temperature of the air flow through distributor head 5 accordingly.

The method of the present invention will now be described with reference to the drawings. Air from the room is first purified as it is drawn from the room and passes through filter 18. It is then moved by the pump 22 in a progressive flow along restricted passage 56. For best results the volume or rate of air flow produced in passage 56 is low and preferably on the order of 3 to 5 c.f.m. The temperature and flow rate of the air flow in passage 56 is then selectively changed by passage through the temperature exchange chamber 24. The air flow through separate passages 53 and 54 is regulated by valve 57 so that heated air from passage 53, cooled air from passage 54, or a mixture of both is passed from chamber 24. Valve 57 is selectively set by adjusting the control dial and the interconnected associated control circuitry 26 as previously described. The air flow passing from the chamber 24 is directed in a diffused pattern under the bed covering by passage through conduit 7 and the long narrow passage in the distributor head 5 so as to circulate in a progressive flow about the body of the bed occupant.

From the foregoing, it is apparent that the method and apparatus as above described provides a constant replacement of air at a selected temperature about the body which will allow natural body evaporation of perspiration to occur which greatly improves relaxation. It is much smaller in volume than conventional room air conditioners providing substantial cost savings and may be easily transported from one location to another and applied to all forms of beds.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that changes in details of structure and system components may be made without departing from the spirit and scope thereof.

I claim:

1. Apparatus for regulating the temperature and humidity about the body of a bed occupant disposed under at least one porousbed covering by circulating air in a progressive flow about the occupants body, said apparatus comprising a double chambered bellows having inlet passages and discharge passages for each chamber and valves at said inlet and discharge passages, a drive for moving said double chambered bellows in a reciprocating movement to draw air mto the inlet passages and through its associated valves producing a continuous low pressure progressive air flow through said bellows discharge passages and along a restricted passage at the discharge passage of the bellows, a temperature exchange chamber having an inlet connected to the restricted passage and inclusive of separate air heating and air cooling passages through which the air flow from said bellows outlet is selectively passed, said heating passage having a heater element for heating the air passing through the heating passage, said cooling passage having a cooling element connected to a refrigerating source to cool the cooling element and the air passing through the cooling passage, control means for selectively varying the temperature and rate in the discharge flow of air passing from said chamber, said control means including body selector means, a valve means in the air discharge of the temperature exchange chamber, a valve drive means for changing the setting of the valve, and circuit means coupled between said body selector means and said valve drive means for regulating the valve drive means and thereby the valve setting in accordance with a selected body requirement, and a distributor head including a conduit connected to the valve outlet and having a diffuser head at its discharge end, said distributor head including spaced upper and lower surface portions forming an elongated narrow passage in communication with said conduit for receiving the air from said chamber and directing it in a diffused pattern under said layer of the bed covering under said pressure provided by said bellows.

2. Apparatus as set forth in claim 1 wherein said circuit means includes an electric servo control system which permits movement of said valve drive means until a selected valve setting is reached.

3. Apparatus as set forth in claim 1 wherein said bellows and said valve drive means are powered by a common drive motor.

4. Apparatus for regulating the air temperature and humidity about the body of a bed occupant disposed between upper and lower layers of a porous bed covering by circulating air in a progressive flow about the occupants body, said apparatus comprising a positive pressure air pump for delivering a low volume constant capacity air output in a unidirectional non-pulsating flow through an outlet of the pump, a temperature exchange chamber having an air heating passage and an air cooling passage through which said flow of air is selectively passed from a common air inlet in flow-receiving relation to the outlet of said pump, said heating passage having a heating element from heating air passing through the heating passage, said cooling passage having cooling element for cooling air passing through the cooling passage, control means for selectively varying the rate and temperature and discharge flow of air passing from said chamber, said control means including an air mixing valve in the outlets of said passages, a valve drive and a control circuit responsive to room temperature and a manual selection for activating said drive, and distributing means having upper and lower surfaces defining an elongated passage and secured in sealing relation to the upper and lower layers of bed covering, respectively, for receiving the air flow from said chamber and directing it in a diffused pattern between the upper and lower layers of the bed covering under pressure provided by said pump means; said control circuit including an electric null circuit for actuating said valve drive and having a first resistance varying with room temperature and a second resistance varying with a manual selection to change the setting of said valve.

References Cited UNITED STATES PATENTS 1/1938 Gaugler 16546 9/1960 Fisher 103l48 US. 01. X.R. 

